When a vehicle travels the road with the posted speed limit, it is often appropriate to monitor adherence by the vehicle to the posted maximum speed. The adherence does not have to be a strict one. It is sufficient for the vehicle to travel within five-ten miles/hour of the posted maximum speed. Usually the maximum posted speed is enforced by the police road patrol.
Monitoring adherence by the vehicle to a route or schedule is well known in the prior art.
Gray in U.S. Pat. No. 4,651,157 discloses a security monitoring and tracking system for a terrestrial or marine vehicle that uses navigational information to determine the latitude and longitude of the vehicle.
U.S. Pat. No. 4,814,711, issued to Olsen, discloses a survey system for collection of real time data from a plurality of survey vehicles, each of which determines its present location using global positioning system (GPS) signals received from a plurality of GPS satellites. A central station periodically polls each survey vehicle and receives that survey vehicle's present location coordinates by radio wave communication. The central station compares that vehicle's path with a survey pattern assigned to that vehicle. The geophysical data measured by a vehicle are also received by the central station and are coordinated with that vehicle's location at the time it was taken.
Harker discloses in U.S. Pat. No. 5,177,684 a method for analyzing transportation schedules of a transportation vehicle to produce optimized schedules. The method uses information on the vehicle's assigned path and the average speed and mobility of the vehicle, and determines a realistic, optimum schedule, including arrival and departure times, that the vehicle can adhere to along that path.
U.S. Pat. No. 5,243,530 issued to Stanifer discloses a system for tracking a plurality of terrestrial, marine or airborne vehicles, using a local area network and packet communication of location information. Loran-C signals are received by a receiver/processor/transmitter on a vehicle, the vehicle's present location is determined, and this location information is transmitted to a central station, using LAN packet protocols, acknowledgment signals and backoff/re-transmission procedures that are standard in the LAN art. If a given vehicle's present location is not received by the central station within a time interval of selected length, the central station requests transmission of the present location from that vehicle.
What is needed is an approach that allows one to automatically match the vehicle's speed with the maximum posted speed and to control the vehicle's speed if it substantially exceeds the posted limit. It would allow enforcement of the vehicle's maximum speed without the police patrol or with reduced police patrol, which is of interest to owners of fleets of vehicles, such as trucking companies. Such compliance would save the fleet owners money.